Apparatus for curing building blocks

ABSTRACT

Freshly made concrete blocks are placed on racks which are suitably disposed in a kiln and steam is introduced by means of a syphon which communicates with the atmosphere and causes the transmittal of the steam along with air which results in the &#39;&#39;&#39;&#39;green&#39;&#39;&#39;&#39; blocks being capable of withstanding higher temperatures than would otherwise be the case; the elements in the air imparting increased tendency of the cement to set and harden.

United States Patent Estis Aug. 29, 1972 [54] APPARATUS FOR CURINGBUILDING 1,348,775 8/1920 Bellonby ..25/ 133 BLOCKS 2,354,773 8/ 1944Ray ..25/l33 UX 2 I t Y [7 i or Lomue J f Moblle Ala Primary ExaminerH.A. Kilby, Jr. [7 Asslgneer p Mobile, Ala. Att0rney-Robert U. Geib, Jr.[22] Filed: Jan. 22, 1970 [57] ABSTRACT [21] Appl. No.: 4,989

Freshly made concrete blocks are placed on racks which are suitablydisposed in a kiln and steam is introduced by means of a Syphon whichCommunicates a a 0' t ph d causes h t i t l f h [58] Field of Search..25/132, 133,147, 143,149, Steam along with air which results in the5/150 blocks being capable of withstanding higher tempera- [56] R f Ctedtures than would otherwise be the case; the elements e erences in theair imparting increased tendency of the cement UNITED STATES PATENTS toSet and'hardm 2,563,408 8/1951 Luzzatti et a1. ..25/l33 2 Claims, 2Drawing figures APPARATUS FOR CURING BUILDING BLOCKS It is among theobjects of the invention to attain a uniform temperature throughout thecuring kiln which results in cured concrete blocks which possess highercompressive strength than is obtainable by conventional methods over thesame period of time, whether it be overnight, or at 7and 28day periods.

Another object is the reduction of shrinkage in the cured concreteblocks.

Still another object is to provide a steam treatment for the purposesdescribed wherein less steam is required than would otherwise be thecase.

A further object is to attain the foregoing ends with apparatus which isdurable in service, and inexpensive to install, operate and maintain.

Still further objects, and the nature and advantages of the invention,are made clear in the following description, and the annexed drawingspresent the best form of the invention presently known to me. However,this disclosure is by way of example only, and changes not shown hereinmay be made without deviation from the principles of the invention ofmaterial alteration of any of the essential characteristics as definedin the appended claims.

In said drawings:

FIG. 1 is a fragmentary elevational view, partly in section, whichdiscloses an operative embodiment of the apparatus of the invention; and

FIG. 2 is an enlarged fragmentary elevational view illustrating theinner and outer pipes or tubes which communicate with the interior ofthe curing kiln for purposes which will be later described.

Referring more particularly to the drawings, the curing kiln of theinvention comprises a floor 3, sidewalls 4, backwall 6, front openingprovided with a door (not shown) and a roof 12; all of which are made ofsuitable materials in the manner known in the art.

Adjacent the bottom of the backwall 6 is a horizontally extendingcircular aperture which receives a pipe or tube 14, the latterprojecting from the outer surface of the backwall and being connected toone end of the line passage of a Tee-fitting 18.

The other end of the line passage of the Tee-fitting 18 is provided witha closure plate 22 having therein a centrally disposed aperture ofconsiderably lesser diameter.

concentrically disposed in the pipe 14 is a pipe or tube 24 ofsubstantially smaller diameter. This inner pipe 24 terminates short ofthe inner end of the larger pipe 14, as shown.

Adjacent the inner end of the inner pipe 24 and on its outer surface isa series of jet mixing fins 28 which are angularly disposed with respectto the axis of this pipe.

The outer end of the inner pipe 24 projects for an appreciable distancefrom the centrally apertured closure plate 22 on the fitting l8 and isconnected to elbow 30 which communicates with the lower end of avertically disposed pipe 32. The upper end of the vertically disposedpipe extends above the roof 12 of the kiln and is connected, through anelbow 34, with a steam main 36, which communicates with a suitable steamboiler (not shown) and is provided with an electrically operated valve38.

This electrically operated valve 38 is controlle through a thermostaticswitch generally indicated at 40.

Further control of the steam which is supplied to the inner pipe 24 isprovided by a valve 42 in the vertically disposed pipe 32.

The branch of leg portion of the Tee-fitting I8 is connected to thebottom of a vertically disposed pipe 46, the upper end of whichterminates into proximity with the roof 12 an is connected through anelbow 48 with a pipe 50 which extends through the backwall 6 andprojects therefrom into communication with the upper portion of theinterior of the kiln.

A valve 52 in the vertically disposed pipe 46 permits the introductionof atmospheric air and controls the quantity of air introduced. 7

In the operation of the apparatus, freshly made blocks of concrete areplaced on racks (not shown) which are placed within the curing kiln 2;and steam is supplied through the steam main 36, vertically disposedpipe 32, Tee-fitting 18 and inner pipe 24 into the kiln adjacent itsbottom. As this is done, outside air is pulled into the kiln throughvalve 52 by syphon action of inner pipe 24 located in outer pipe 14.

The steam and outside air mixture, after flowing through the kiln in themanner illustrated by the arrows, leaves the upper portion of the kilnthrough the horizontal pipe 50, and it pulled through syphon actionthrough the vertically disposed pipe 46, and branch or leg portion ofthe Tee-fitting 18, around the exterior of the inner pipe 24 and movesbetween the angularly disposed tapering jet mixing fins 28 and out ofthe inner end of the horizontally extending pipe 14 back into the kiln,causing forced circulation action therewithin.

A suitable quantity of atmospheric air is supplied to the outer pipe 14through the valve 52 in the vertically disposed recycling pipe 46; andsteam is provided through inner pipe 24 at a pressure which may beacceptably around pounds per square inch, this being more or less basedon the size of the kiln.

Steam at a suitable pressure results in the syphoning into the kiln ofan appreciable amount of atmospheric air, which permits the use ofhigher and more even temperature in the curing process.

The higher temperature within the kiln, and the mixture of steam andatmospheric air result in l. Attainment of uniform temperaturethroughout the kiln in a manner which is much quicker than in the caseof conventional kiln which have steam injected thereinto, but wherein noatmospheric air is introduced. 2. Much greater compressive strength inthe cured blocks overnight, as well as at intervals of 7 days and 28days. 3. Reduced shrinking of the cured concrete blocks. and 4. Therequirement of less steam.

Having thus described the invention, what I claim as new and desire tosecure by Letters Patent is:

1. Apparatus for curing cementitious articles such building blocks whichcomprises a kiln for receiving the cementitious articles said kilnhaving an intake port and an exhaust port a steam supply pipe ofsubstantially smaller diameter extending into the intake port and inaxial alignment therewith a conduit communicating with said exhaust portand with the space between the inner surface of said intake port and theouter surface of the steam pipe which is disposed coaxially therein andmeans for supplying atmospheric air to said conduit 2. The apparatus ofclaim 1, together with means disposed between the inner wall of saidintake port and the outer wall of said steam pipe for imparting aswirling motion to the mixture of steam and gas passing therethrough.

1. Apparatus for curing cementitious articles such building blocks whichcomprises a kiln for receiving the cementitious articles said kilnhaving an intake port and an exhaust port a steam supply pipe ofsubstantially smaller diameter extending into the intake port and inaxial alignment therewith a conduit communicating with said exhaust portand with the space between the inner surface of said intake port and theouter surface of the steam pipe which is disposed coaxially therein andmeans for supplying atmospheric air to said conduit the inner end ofsaid steam supply pipe terminating short of the inner end of said intakeport in which it is coaxially disposed, to thereby produce a siphoningeffect on the recirculating steam and atmospheric air moving through thespace between the outer surface of said steam supply pipe and the innersurface of said intake port.
 2. The apparatus of claim 1, together withmeans disposed between the inner wall of said intake port and the outerwall of said steam pipe for imparting a swirling motion to the mixtureof steam and gas passing therethrough.